Low-percentage manganese steel



l retested Dec. 26, 1922, I I M l STATES .PATET OFFICE;

JUD M. BLAKE, OF CHICAGU HEIGHTS II LINOIS, ASSIGNOR 'IO AMERICAN MANGANESE STEEL COMPANY, OF CHICAGO, ILLINOIS; CORPORATION OF MAINE.

, LOW-PERCENTAGE MANGANESE STEEL. no Drawing. Application filed Jul a, 1919. Serial to. 309,567.

- To all w'h'om z'tgmay concern. shut off and the casting allowed to cool with Be. it known that I, Jon M. BLAKE, acitthe furnace. For certain classes of work it is izen ofthe United States, residin at Chi desirablefto permit castings to cool'quickly Icago Heights, in the county of ook and and in other classes of work to cool slowly.

5 State of Illinois, have invented new and Low manganese steel castings made in accord= so useful Low-Percentage Manganese Steel; of ance' with this invention may be cooled which the following is a specification. quickly by removing the castings from the An object of the present invention-is to furnace after the same have been subjected produce a steel which. will have a degree of. to heat treatment for cooling in the air and hardness that will adapt it to resist erosion may be cooled slowly by permitting the cast- 65 or wear, with a low coefliciency of flowing ings to remain in theheat treatment furnace action. so that the temperature of the castings will Commercialmanganese steel usually confall with that of the furnace, The hardness taining from 10.to 14% manganese has been thus obtained will be suitable for many com- I '15 found to be unsuccessful for many commer-- mercial purposes. a Y

clal purposes, owing tothe flowing action of; If, however, a greater hardness is required, I the steel under the influence of the forces and particularly if a high degree of toughwhich it'encounters in use, for instance, pan ness is not needed in the commercial purpose 7 bottoms, roll tires, and scrapers employed in for which the casting is intended, the cooling the wet grindingof clay in the manufacture may be permitted to proceed more rapidly, 75

' of fire bricks. r as by cooling the castings in the open air, or I have found. by experiment that a very in a furnace'without applied heat or with a satisfactory steel can be produced for the modified application of heat. i

foregoing purposes, as well as other uses 1 claim: v where similar forces are encountered, by add- 1; A commercial steel containing man- 80 mg .to-a good commercial grade of steel pro-- ganese and carbon in the pro'portlons of duced by the open'hearth, Bessemer, or elecabout 4.25% manganese and .42 of carbon. tric furnace processes, a very much smaller 2. The herein-described process of producpercentage of manganese than is employed in ing articles of low percentage manganese 8o ordinary commercial manganese steel. I steel, which consists in adding, to a suitable as prefer to employ for this purpose from 3.50 bath of molten steel, manganese in the proto f manganese. I have found in portion ofnot over 4.50%, pouring the steelpractlce that good results are obtained by to produce'the castings, subjecting the-castusing 4.25% ofmanganese in a steel conings to heat treatment in an annealing furtaining about 42% of 'carbon'and 25% of nace at-1325 F, to 1375 F. until the heat 90 silicon. The analysis of phosphorus in the has fully penetrated the entire section of the steel tested was .07 while its-sulphur con castings, and then allowing the castings to tent was O3%. These constituents, however, 'cool in the atmosphere. L aggregating about .10% which I regard as- 3. The herein-described process of producimpurities and as not bearing upon the reing articles of low, percentage manganese 95 sult obtained. v i ,steel, which consists in adding,'to a suitable In producing the steel, the manganese'conbath of molten steel, manganese inthe protent is added to the heat after. the'steel is portion of not-over 4.50%, pouring the steel otherwise developed by any improved known to produce the castings, subjecting the castprocess, and the heat is then mired. to pro ings to 'heat treatment in an annealing fur 100 duce the commercial articles d esi'red. After nace at 1325 to 1375" F. until the heat has. pouring, the cooling of the castings is pref- ,f u'lly' penetrated the entire section of the erablycontrolled. in order to regulate the castings, and, then allowing the castings to degree of hardness obtained For instance, cool in the furnace v i x the castings may -beplaced ina suitable an- .4, Annealed cast steel containing about 105 l nealing'furnace andsubjected to heat treat- 4.25% of manganese, about .42% of carbon ment of from 1325 to 1375 F., the furnace and about 25% of silicon. being held at this temperature until the heat Signed at Chicago Heights, Illinois, this has thoroughly penetrated the entire section third day of July, 1919.

' of the casting, after which the furnace is j JUD M, BLAKE. 

